diff --git a/nixos/modules/tasks/snapraid.nix b/nixos/modules/tasks/snapraid.nix
index ff956f306709..c8dde5b48993 100644
--- a/nixos/modules/tasks/snapraid.nix
+++ b/nixos/modules/tasks/snapraid.nix
@@ -207,7 +207,7 @@ in
             SystemCallArchitectures = "native";
             SystemCallFilter = "@system-service";
             SystemCallErrorNumber = "EPERM";
-            CapabilityBoundingSet = "CAP_DAC_OVERRIDE" ++
+            CapabilityBoundingSet = "CAP_DAC_OVERRIDE" +
               lib.optionalString cfg.touchBeforeSync " CAP_FOWNER";
 
             ProtectSystem = "strict";